The victories came after Democrats clinched control of the Senate, and with President Barack Obama's re-election. Democrats won competitive races in Virginia, Ohio and Florida and picked up Republican-held seats in Indiana and Massachusetts. Republicans also lost a seat to independent Angus King in Maine, a former Democratic governor.

As of 12:30 a.m. Wednesday, Democrats had locked up 52 seats, including independent Bernie Sanders, who aligns himself with them. Officials also expect King will caucus with Democrats. Republicans locked up 44 seats, three fewer than they have now.